The use of linerless labels is becoming widespread due to relatively low cost of such labels and due to their relative environmental friendliness. A number of different dispensers has been developed--such as shown in U.S. Pat. Nos. 5,375,752 and 5,417,783, European published application 0577241, and co-pending U.S. application Ser. No. 08/312,068 filed Sep. 26, 1994--to facilitate dispensing of such labels. Each of those dispensers is particularly suited for certain dispensing requirements and can successfully dispense linerless labels without prohibitive difficulties. However, there are some circumstances for which such dispensers are not ideally suited, and therefore the linerless label dispenser according to the present invention--and its associated cutting mechanism--have been developed.
The linerless label dispenser, and its associated cutting mechanism, according to the present invention are ideally suited for dispensing linerless labels from a roll even when the labels are not perforated on the roll. The dispenser can automatically print the labels just prior to dispensing, and dispenses them in a manner that substantially avoids jamming of the printer or the cutting mechanism.
According to one aspect of the present invention a linerless label dispenser is provided comprising the following components: A support for a supply of continuous form linerless labels, each label having a pressure sensitive adhesive face and an adhesive-release material coated face. An adhesive-release material guide structure for engaging the adhesive face of labels from the supply of labels. A print head, on the opposite side of the guide structure from the supply of labels, for printing the release material coated face of labels from the supply of labels. A stripper surface on the opposite side of the print head from the release material structure, the stripper surface of adhesive-release material. A stationary anvil blade, on the opposite side of the stripper surface from the print head, for engaging the adhesive face of labels from the supply of labels. And an automatic rotary cutter cooperating with the stationary anvil blade for engaging the release material coated face of labels from the supply of labels, and cutting individual labels to be dispensed from the supply of continuous form of linerless labels.
The support for the continuous form linerless labels preferably comprises a conventional shaft for supporting the core of a roll of linerless labels. The linerless labels may either be perforated, or may have marks applied thereto indicating the approximate position at which the web of labels from the roll are to be severed into individual labels.
The adhesive-release material guide structure may be mounted adjacent a plastic guide which engages the release material face of the labels, and preferably the adhesive-release material thereof is a plasma coating such as disclosed in U.S. Pat. No. 5,375,752, the disclosure of which is hereby incorporated by reference herein.
After the guide structure of the labels typically pass under a sensor which either senses the perforations or marks indicating the division between labels, which cooperates with a control mechanism for the printer and subsequent rotary cutter. The print head may be of any conventional type that is capable of printing on the release material, preferably a non-impact printer such as an ink jet printer. Where a thermosensitive coating is also provided for the labels, the print head may be a thermal print head or a thermal transfer print head. Typically the print head cooperates with a print roller, which also is plasma coated. (The print roller in the case of thermal or ink jet is made of a silicone covered core, available from Silicone Products & Technology, Inc. of Lancaster, N.Y.)
Just downstream of the print head is a support which supports the stripper surface and the stationary anvil blade, the stripper surface preventing adherence of the labels to the print roller and enabling passage of the labels downstream to the rotary cutter without adherence to parts of the dispenser. The adhesive-release material of the stripper surface preferably also is a plasma coating, and the stripper surface is disposed at an upwardly directed (from the print head) angle of between about 20-35.degree. (preferably about 27.degree.) with respect to the horizontal so that the labels printed by the print head move upwardly at an angle from the print head to the rotary cutter. The provision of such an angle has been found to minimize jams of the printer and the cutter. A stripper surface also may have a plurality of upwardly extending extensions formed on at least a part thereof (e.g. a portion of between 5-20% of the width of a linerless label passing thereover) for decreasing the surface tension thereof.
The stationary anvil blade is preferably also plasma coated and is immediately adjacent the stripper surface. Alternatively, the stationary block may be painted with a textured paint. (The actual cutting surfaces are not plasma coated or textured painted, just the supporting pieces.) It has been found according to the present invention that jamming of the printer and rotary cutter are minimized if the anvil blade is spaced downwardly from a stripper surface a sufficient distance to insure that the leading edge of the label (the edge being cut) is not smashed. It has been found that a spacing of between about 0.001-0.008 inches (preferably about 0.002-0.004 inches) is most effective.
The rotary cutter may comprise a conventional off the shelf structure, except for the plasma coated rotary blade, such as a Hitachi rotary cutter Model #V15A.
Under some circumstances it is desirable to have an exit roller downstream of the rotary cutoff mechanism to facilitate dispensing of the cut labels, such as through an exit opening in a housing. Such an exit roller, when provided, also preferably has a plasma coated surface, and that surface is also preferably grooved (between about 5-20% of the width of a linerless label engaged thereby) and typically cooperates with a hold down mechanism of any conventional type.
According to another aspect of the present invention a cutting mechanism per se for linerless labels (each having a pressure sensitive adhesive face and an adhesive-release material coated face) is provided. The cutting mechanism comprises the following elements: A stripper surface of adhesive-release material for engaging the adhesive face of linerless labels, and making an angle with respect to the horizontal of between 20-35 degrees. A stationary anvil blade adjacent the stripper surface for engaging the adhesive face of linerless labels. And a rotary cutter cooperating with the stationary anvil blade for engaging the release material coated face of linerless labels and cutting the labels.
The rotary cutter typically includes a rotary blade and the stationary and rotary blades are preferably plasma coated or texture painted. The orientation and dimensioning of the stripper surface and anvil blade preferably are as described above for the dispenser.
It is a primary object of the present invention to provide an effective linerless label dispenser and a cutting mechanism for use therewith. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.